Definitely a little hard to find, search for "The Asadang" on a maps app and then walk away from the river and turn right down a little alley, the Airbnb is at the end of that alley on the right.
Besides being a tad difficult to locate, the stay was fabulous! Could've used a bit more toilet paper, and the bed sheets tended to come off fairly easily, but other than that, no complaints! Beautiful area, right in the middle of Old Town.
Also the cost of the stay was an absolute steal. Would definitely stay here again!